Repair or Lifter Craft. This is what i have suggested already. In these roles it would fit with Discovery, but not as a fighter.
@ Xing: Please remind the hints i have given to you about modelling. Just finish one half first, including the texture, then copy part by part and flip them left right or vice versa. This will give you an exactly centered and symmetrical model.
I'm just trying to add some new ideas that people might like, people might not. If you are going to hate me just for bringing ideas, well, I really have no comment for that.
First off, it is NOT giant. it's like the size of two rhino one over the other.
And it WONT have arms, it WONT have a head. It would looks like the coalition ships you see at the begining of the intro movie.